An accelerator pedal of a vehicle has a hysteresis mechanism, which sets a force difference between a pedal depression force at a pedal depressing time and a pedal depression force at a pedal releasing time. For example, a patent document 1 (i.e., Japanese Patent application No. 2012-222056) discloses an accelerator pedal device that is equipped with a friction member disposed at a position between a pedal boss that rotates together with a shaft and a support member that supports the rotating shaft.
The friction member of the accelerator pedal device in the patent document 1 applies a pressing force from the friction member itself to an inner wall of the support member according to a magnitude of the pedal depression force at the pedal depressing time. If the pressing force from the friction member is excessive, the support member breaks and an accelerator pedal return spring housed in an inside of the support member is exposed to an outside of the support member. When the return spring is exposed to the outside of the support member, the return spring may easily fall out of the support member, leaving the accelerator pedal in a state where the accelerator pedal may not return to a fully closed position.